Autoclave pressure cooker

Another Methodfor 5 5-Diethyl Barbituric Acid. (This is a scaled down version.) 16 g of clean sodium is dissolved in 300 g of absolute ethanol. To this cooled solution is added 20 g of dry urea and 50 g of diethyl malonic ester (diethyl diethyl malonate). The mixture is heated in an autoclave (pressure cooker, very strong) for 4 to 5 hours at 100-110°. After removing from the autoclave, the mixture is cooled. Upon cooling, the sodium salt of diethyl barbituric acid separates, is filtered off, dissolved in water, and the free acid precipitated by the addition of hydrochloric acid. The acid is filtered and recrystallized from water, using decolorizing carbon, if necessary. Yield Depends on your ability to exclude H2O from the beginning of reaction. 

The media is sterilized in an autoclave (pressure cooker) for 30 minutes and allowed to cool in the pressure cooker. When the sides of the pressure cooker are just a little warm to touch the media is ready to pour into the sterilized Petri dishes. If the media is not allowed to cool it will form water condensation in the dishes and increases the rate of contamination. If the media is allowed to cool too much it will gel and then will not pour. 

Curing can be performed in several devices heated mold (Figure 1-13), hot press (heated plates that are forced together), and an autoclave which is essentially a very large version of an ordinary kitchen pressure cooker as in Figure 1-21. 

It is recommended to autoclave glass dishes and medium separately. If your dishes are autoclaveable, you may dispense the agar into the dish and then autoclave it. In this case it is best to cool the dishes in the autoclave or in the pressure cooker to reduce the amount of water that will condense on the cover of the dish. 

Taylor CR, Shi S-R, Chen C, et al. Comparative study of antigen retrieval heating methods microwave, microwave and pressure cooker, autoclave, and steamer. Biotech. Histochem. 1996 71 263-270. 

Other heating equipment. Autoclave used for sterilization can be used to achieve superheating condition at 120°C. For higher temperature heating, a domestic pressure cooker, or a plastic steamer may be used. Some commercial laboratory pressure cookers have been designed for AR-IHC with controlled temperature. A water bath can be used to achieve lower temperature heating condition. 

Antigen retrieval place sections in a Coplin jar with antigen retrieval solution of choice (e.g. 10 mM citrate acid, pH 6) and heat at 90°C 110°C (depending on tissue) in a microwave, steamer, domestic pressure cooker or autoclave. See Sect. 6.1.1. 

There are several variations of HIER. Many laboratories have attempted to improve the original method by altering the buffer solutions as well as the source and mode of heating. Currently, the most popular HIER technologies use stainless steel or plastic pressure cookers, microwave ovens, or autoclaves as the heat source and low-molarity buffers with acidic or alkaline pR (6,7,9-12). 

A wide variety of heating devices have been introduced for use in HIER. Among these, the microwave oven (MWO), commercial pressure cooker (PC), and autoclave (AC) have proven to be the most employable. 

Most methods employ temperatures near or beyond 100°C. Heating above the atmospheric boiling temperature is possible in traditional or in microwave pressure cookers as well as in autoclaves (see Subheading 1.1.2.), In a commercial PC, the operating pressure is about 103 kPa/15 psi, which results in 120°C temperature (19). The same temperature is employed in wet autoclave HIER protocols (10,15,19). 

The pressure cooker-microwave heating method is simpler than the autoclave procedure and more efficient than microwave heating alone. The pressure cooker does not require checking the level of the antigen retrieval solution during heating in the microwave oven, and a large number of slides can be loaded simultaneously. In addition, the pressure... 

The most commonly accepted point of view is that heat is responsible for unmasking the epitopes. In fact, Battifora (1996) has introduced the phrase heat-induced epitope retrieval (HIER). Heating at KXPC is a powerful treatment that can unmask hidden, buried, or crosslinked epitopes. Heat can be provided not only by a microwave oven, but also by an autoclave, a pressure cooker, steam, or a hot plate. A consensus on which method of heating is most effective in the retrieval of all types of epitopes is lacking. Therefore, some... 

The prepared medium is dispensed into screw cap bottles (prescription ovals 125 ml to 250 ml capacity), which should never be filled more than two-thirds full. Bottles of the freshly prepared medium are capped loosely and sterilized in an autoclave or pressure cooker for 15 minutes at 15 pounds pressure (120°C). When the medium has been sterilized and cooled the caps should be tightened upon removal from the autoclave or pressure cooker, and stored in a cool place. 

When it is desired to sterilise only a small amount of material the use of an autoclave may be extravagant. In this case an ordinary pressure cooker with facilities to go up to 15 lb pressure may be used, but precautions must be taken to allow adequate time for cooling before the cooker is opened. 

When set to 15 psi, an autoclave, like a pressure cooker, will achieve a temperature of about 120 °C at full pressure (12-13). 

Failure to achieve the optimal temperature required for heat induced antigen retrieval. When using a waterbath or steamer, allow sufficient time for the retrieval buffer to equilibrate to a temperature range of 95-99 °C. At high altitude (greater than-4,500 feet), the buffer will boil at less than 95 °C. Utilize a closed heating system such as a pressure cooker, autoclave or Pascal, or utilize a low temperature protocol if standardization of the validated procedure is not affected. 51-65... 

Despite some successes with the above pretreatments, the development of wet heat-induced epitope retrieval (HIER) procedures, which involves heating the fixed tissue sections in dilute metal-salt or buffer solutions at or above 100°C, for several minutes to 1/2 h, was the critical breakthrough in paraffin section immunohistochemistry (2, 7-9). Today, there are many variations of the original HIER technique. These differ primarily in the recommended buffer solutions and/or the source or mode of heating, but the basic formula of wet heat treatment over a fixed time period is similar. The most popular HIER technologies use microwave ovens, stainless steel or plastic pressure cookers, autoclaves, vegetable steamers or water-baths as the heat sources and low molarity buffers with acidic or alkaline pH (8,9,11-14). 

Heating Devices A wide variety of heating devices have been adapted for use in HIER, including microwave ovens (MWO), pressure cookers, vegetable steamers, autoclaves, and water-baths. The most reproducible results may be achieved with MWOs that incorporate time and temperature control even above the atmospheric boiling point (combined with a plastic pressure cooker). The archetypes are the professional laboratory microwave instruments, which... 

---